3O6F

Crystal structure of a human autoimmune TCR MS2-3C8 bound to MHC class II self-ligand MBP/HLA-DR4


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.239 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structure of a TCR with high affinity for self-antigen reveals basis for escape from negative selection.

Yin, Y.Li, Y.Kerzic, M.C.Martin, R.Mariuzza, R.A.

(2011) Embo J. 30: 1137-1148

  • DOI: 10.1038/emboj.2011.21

  • PubMed Abstract: 
  • The failure to eliminate self-reactive T cells during negative selection is a prerequisite for autoimmunity. To escape deletion, autoreactive T-cell receptors (TCRs) may form unstable complexes with self-peptide-MHC by adopting suboptimal binding top ...

    The failure to eliminate self-reactive T cells during negative selection is a prerequisite for autoimmunity. To escape deletion, autoreactive T-cell receptors (TCRs) may form unstable complexes with self-peptide-MHC by adopting suboptimal binding topologies compared with anti-microbial TCRs. Alternatively, escape can occur by weak binding between self-peptides and MHC. We determined the structure of a human autoimmune TCR (MS2-3C8) bound to a self-peptide from myelin basic protein (MBP) and the multiple sclerosis-associated MHC molecule HLA-DR4. MBP is loosely accommodated in the HLA-DR4-binding groove, accounting for its low affinity. Conversely, MS2-3C8 binds MBP-DR4 as tightly as the most avid anti-microbial TCRs. MS2-3C8 engages self-antigen via a docking mode that resembles the optimal topology of anti-foreign TCRs, but is distinct from that of other autoreactive TCRs. Combined with a unique CDR3β conformation, this docking mode compensates for the weak binding of MBP to HLA-DR4 by maximizing interactions between MS2-3C8 and MBP. Thus, the MS2-3C8-MBP-DR4 complex reveals the basis for an alternative strategy whereby autoreactive T cells escape negative selection, yet retain the ability to initiate autoimmunity.


    Organizational Affiliation

    Institute for Bioscience and Biotechnology Research, University of Maryland, WM Keck Laboratory for Structural Biology, Rockville, MD, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DR alpha chain
A, E
182Homo sapiensMutation(s): 0 
Gene Names: HLA-DRA (HLA-DRA1)
Find proteins for P01903 (Homo sapiens)
Go to Gene View: HLA-DRA
Go to UniProtKB:  P01903
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DRB1-4 beta chain
B, F
221Homo sapiensMutation(s): 0 
Gene Names: HLA-DRB1
Find proteins for P13760 (Homo sapiens)
Go to Gene View: HLA-DRB1
Go to UniProtKB:  P13760
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
T-cell receptor alpha chain C region
C, G
206Homo sapiensMutation(s): 0 
Gene Names: TRAC (TCRA)
Find proteins for P01848 (Homo sapiens)
Go to UniProtKB:  P01848
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
T-cell receptor beta-1 chain C region
D, H
245Homo sapiensMutation(s): 1 
Gene Names: TRBC2 (TCRBC2)
Find proteins for A0A5B9 (Homo sapiens)
Go to UniProtKB:  A0A5B9
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.239 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 102.480α = 90.00
b = 218.403β = 90.00
c = 98.412γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
PHASERphasing
HKL-2000data scaling
HKL-2000data collection
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-03-02
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2011-09-07
    Type: Database references
  • Version 1.3: 2017-08-09
    Type: Advisory, Refinement description, Source and taxonomy